OFFSET
1,2
COMMENTS
Superdiagonal 3 of A268115.
EXAMPLE
Some solutions for n=4
..0..0..0..1..2..2..3....0..0..0..1..1..2..3....0..1..1..2..2..2..3
..0..1..1..1..2..3..3....0..0..1..1..1..2..3....0..1..2..3..3..3..0
..0..1..2..2..2..3..0....0..1..2..2..2..3..3....1..1..2..3..3..0..0
..1..2..3..3..3..0..1....0..1..2..2..3..3..3....1..2..2..3..0..0..1
CROSSREFS
KEYWORD
nonn
AUTHOR
R. H. Hardin, Jan 26 2016
STATUS
approved